The present invention relates generally to integrated circuit packaging, and more specifically to testing and burning-in integrated circuit die prior to their being assembled into a final integrated circuit package.
One of the ongoing challenges facing the manufacture of integrated circuit packages is the availability of known good die. This becomes even more significant in the case of multi-chip modules or integrated circuit packages which incorporate more than one die into a package. To achieve the required yields to produce an affordable and reliable multi-chip package, the reliability of the individual die must be determined prior to assembly. Typically, this has been accomplished by electrically connecting each die to test equipment and testing the electrical operation of the die. The die may also be put through a burn-in process which places the die in an elevated temperature environment during its operation causing a high stress situation for the die. This burnin procedure helps to ensure the die will operate in a wide variety of situations. The testing and burn-in process improves the yield of manufactured packages by only using die which have successfully passed the above described testing and burn-in procedures.
Although the testing and burn-in process improves the yield of packages made using die which have successfully passed the testing and burn-in procedures, there are still problems with the current methods. One difficulty with the current method involves the environment in which the die is during the testing and burn-in of the die. When a die is manufactured into its final integrated circuit package, it is typically hermetically sealed into the package using some form of a ceramic enclosure. However, the current method of testing and burning-in a die leaves the die exposed to the ambient air. This allows ambient particles and moisture to potentially cause an otherwise good die to fail as a result of the test. Also, this exposure to the ambient air allows the corrosion of the die by oxidation. As will be seen, the present invention provides a method and arrangement for testing and burning-in an integrated circuit die in a hermetically sealed, disassemblable prepackage which protects the die frown ambient particles and moisture as well as protecting the die from corrosion due to oxidation.